The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
For each type of optical disc, there exists a multitude of standards that manufacturers adhere to in order for the industry as a whole to produce a variety of conforming and functional products. Blu-ray, also known as Blu-ray Disc (BD) is the name of a recent optical disc standard that is currently replacing the DVD standard. Blu-ray offers more than five times the storage capacity of traditional DVDs and can hold up to 25 giga-bytes on a single-layer disc, and 50 giga-bytes on a dual-layer disc. Unfortunately, the hardware required for Blu-ray players is substantially more expensive than for other optical systems.
Generally, Blu-ray systems are designed using a host of standards that together provide advantage over conventional DVD systems. For example, Blu-ray systems are specified to use a blue-violet laser having a wavelength of 405 nm (as compared to the 650 nm wavelength used by DVDs) and use a higher numerical aperture (NA) than DVDs, i.e., 0.85 for Blu-ray compared to 0.6 for DVDs with a collimator motor to enable Blu-ray systems to reliably read dual layered discs.